Update libktorrent to version 1.3.1
Also add patches to build with latest boost.
The biggest changes since the 4.2 release include:
- Reintroduction of a tabbed torrent list widget, though a bit different
then the old tab widget from the 4.1 days.
- Improved support for magnet links
- Support for removable storage
- A whole bunch of bugfixes and smaller improvements over ktorrent

Bump for perl-5.20.0.
Do it for all packages that
* mention perl, or
* have a directory name starting with p5-*, or
* depend on a package starting with p5-
like last time, for 5.18, where this didn't lead to complaints.
Let me know if you have any this time.

Bump freetype2 and fontconfig dependencies to current pkgsrc versions,
to address issues with NetBSD-6(and earlier)'s fontconfig not being
new enough for pango.
While doing that, also bump freetype2 dependency to current pkgsrc
version.
Suggested by tron in PR 47882

Bump all packages for perl-5.18, that
a) refer 'perl' in their Makefile, or
b) have a directory name of p5-*, or
c) have any dependency on any p5-* package
Like last time, where this caused no complaints.

Add new package net/libktorrent
KTorrent has sbeen split into the application ktorrent and the library
libktorrent. Libktorrent contains all the torrent downloading code and
ktorrent contains all application code and plugins. The goal is to make
libktorrent an independent library which can be used by other
applications.